Ball-mill.



No. 889,491. PATENTED DEC. 25, 1906.

H. LUHNERT. BALL MILL.

APPLICATION FILED JUNE 14, 1904.

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lrfaayaxs TH: uomus PETERS co., WASHINGTON, o c.

HERMAN LOHNERT, OF BROMBERG, GERMANY.

BALL-MILL.

Specification of Letters Patent.

Patented Dec. 25, 1906.

Application filed June 14, 1904- Serial No. 212,587.

To all whom it may concern:

Be it known that I, HERMAN LoHNERT, manufacturer, a subject of the Kingof Prussia, German Emperor, residing at No. 4 Bahnhof strasse,Bromberg,in the German Empire, have invented new and useful Improvements inBall-Mills, of which the following is a specification.

In ball-mills the plates employed for. lining the drum have according toprior practice been secured thereto at both ends by means of one or morescrews with countersunk heads. Experience shows, however, that thescrews very soon fracture or break, and the reason of this is frequentlyattributed to the inferior material of which the screws are made. Thereal reason, however, is that the balls, owing to their continuallyfalling upon the liningplates, cause lengthening of the latter,particularly of the fibers of the surface turned toward the inside ofthe mill, so that the plate becomes more or less buckled or bulged out.In this way the screws are subjected to very great strain, andconsequently break in the course of time.

According to my invention the liningplates are secured by means ofscrews only at one end, while the other end slides below fillets or thelike, which may be presented by the adjacent end of the succeedingplate.

My invention is SllOWIl in the accompanying drawings, in which- Figure 1is a sectional view illustrating the junction of adjacent lining-plates.Fig. 2 is a plan of the plates. Fig. 3 is a plan of a modifiedarrangement, showing similar liningplates each secured by means only ofa single screw.

The lining-plates a are bent eccentrically l to the axis of rotation ofthe drum of the mill, 4.0

l so that they ascend at one end, which elevated or head end dis held bystrong screws 6. The other, or tail end, lies below the head end at ofthe next following plate, or, as shown in Fig. 2, a tongue 0, formed onthe tail end, enters a recess e in the flanged end cl in such mannerthat on extension of the plate a the free tail end slides farther belowthe head end (1 of the succeeding plate. In this way no injurioustension can arise, so that the screws are not subjected to any strain.

In Fig. 3 the tail ends of the plates are shown as having two tongues c,the flange of the head end (i of the next plate being correspondinglycut away at e to receive them.

This arrangement of plates with sliding tail ends presents the furtheradvantage that not more than half the number of screws is necessary.

Having thus described my invention, what I claim as new, and desire tosecure by Letters Patent, is

In a device of the class described the combination with the casing, ofthe lining-plates each having a slotted flange on one end thereof and atongue on the other end adapted to enter the slot of the flange of thesucceeding plate so as to allow of longitudinal movement of the endcarrying the tongue and means for securing one end of the plates to thecasing.

In witness whereof I have hereunto signed my name, this 27th day ofJune, 1904, in the presence of two subscribing witnesses.

HERMAN LOHNERT.

l/Vitnesses WOLDEMAR HAUPT, HENRY HAsPER.

